Abstract:

In Quang Ninh coal mines, for inter-bedded rocks and screen discards (with ash content of more than 60%), the mines often do not treat this type of low grade coals but stockpiling at temporary dumps. Most of Quang Ninh coal mines have large amounts of such low grade coals at the mine sites, sometime with amounts of over a million of tonnes and every year the mines continue to add hundred thousands of tonnes to the dump sites, thus causing waste of resources and environmental pollution. This report is to present the results of the study into clean coal recovery by gravity separation and flotation from high ash coals of over 60% ash of the three mines including Nui Beo, Coc Sau and Khe Sim mines. The obtained clean coals have ash contents of less than 40%, meeting the quality standards for commercial coals and the discard of of over 80% ash, meeting disposal standards.